SOIL Studies

SOIL Studies

2019, Vol 8, Num, 3     (Pages: 070-076)

Analysis of Drought at Different Timescales by Standardized Precipitation Index in Kocadere Basin

Gözen YÜCEERİM 1 ,Gülay YILMAZ 1 ,Merve ETÖZ 1 ,C.Oğuz ACAR 1

1 Uluslararası Tarımsal Araştırma ve Eğitim Merkezi Müdürlüğü, İzmir

DOI: 10.21657/topraksu.655270
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Drought is a natural disaster which affect water resources, agriculture and all living things also causes socio-economic damages. Numerous indices have been developed to characterize the drought, and these indices are widely used for drought monitoring. In this study, frequently used SPI (Standardized Precipitation Index) was calculated for different time periods. Thus, it is aimed to evaluate the guidance of the SPI, which is a meteorological drought index, in terms of agricultural and hydrological drought for different periods. In the study, 30 years (1987-2016) precipitation data which belongs to the Kocadere Basin have been used. The data obtained by considering the water year (1 October – 30 September), from the rainfall stations which were located in basin area. With this data SPI was calculated for 3 different time periods (SPI-1, SPI-6 and SPI-12). Drought severity classes in different periods were determined and precipitation - flow data were used for evaluations. As an evaluation, when the index value fell below zero, is considered as the beginning of the dry season. In this circumstance, the period between 1987-2016 water year is classify as, 48.33% dry, 51.67% rainy for SPI-1; 51.67% dry, 48.33% rainy for SPI-6 and 50.00% dry and 50.00% rainy for SPI-12. Its observed that, SPI-1 values were consistent with measured rainfall and reflect the index value. Moreover, SPI-6 values were found to be a good indicator of precipitation monitoring between october and march, which is an important period for this basin. The annualized index values (SPI-12) clarify the increase and decrease in total annual flows measured in the basin.

Keywords : Drought, Kocadere basin, SPI (standardized precipitation index)